What's up with my Canaryberry?

[ocgreen]

I plunked 4 new blackberry by FastBuds and one came out yellow:

Over time it started developing at same rate as other seedlings. Key difference was all new growth was yellow but leaves were good shape and plant was perky.

Now the oldest growth is starting to turn green:

What is going on here? I nicknamed her Canaryberry but wondering if I should do more.

PH/RH has been fine. Sitting in about 500 ppm mega crop.

 

[9fingerleafs]

are the other 3 the same size? how much darker are they? its not unusual to have a runt, the smaller weaker of the bunch, most of the times they end up being the best buds in my experience

 

[ocgreen]

They are roughly the same size -- 2 are noticeably larger but not by much and the last is basically same.

All other plants are a nice healthy/normal shade of green. Will post a pic of others once lights are on again

 

[ocgreen]

 

[9fingerleafs]

those are the healthy ones?